1. Field of the Invention
This invention relates to a painting device to continuously form a pattern on the surface of a base material such as a thin metal sheet or a plastic film, more particularly a painting device to form a pattern such as a band, stripe or streak on a base material over the whole surface.
2. Prior Art
Conventionally, there has been known a painting device to continuously form a pattern such as a band, stripe or steak on an elongate base material with two kinds of paints used as described in Japanese Patent Publication No. Sho 64-106 which is shown in FIGS. 13 and 14. In this device, a painting groove b has its opening completely sealed off by a base material a and the base material a is continuously moved in a direction shown by an arrow while paints A and B in the painting groove b remains not completely agitated (where they are half mixed), so that a streak pattern is formed on the surface of the basic material a.
In the above-described device, it is essential that the width Wa of the base material a is wider than the width Wb of the painting groove b (Wa&gt;Wb) since the base material a is required to constitute a closing wall to close the opening of the painting groove b. Therefore, the material a has its two sides in the width direction vulnerable to have an unpainted area c (.DELTA.T) left unpainted and painting cannot be applied to the base material a over the whole surface. Such an unpainted area c needs post-painting processing such as slitting, requiring additional facilities and higher cost.